Extra virgin olive oils increase hepatic fat accumulation and hepatic antioxidant protein levels in APOE-/- mice.

We assessed the effects of Picual and Arbequina olive oil, rich and poor in polyphenols, respectively, on plasma lipid and glucose metabolism, hepatic fat content, and the hepatic proteome in female Apoe-/- mice. Both olive oils increased hepatic fat content and adipophilin levels (p < 0.05), though Picual olive oil significantly decreased plasma triglycerides (p < 0.05). Proteomics identified a range of hepatic antioxidant enzymes that were differentially regulated by both olive oils as compared with palm oil. We found a clear association between olive oil consumption and differential regulation of adipophilin and betaine homocysteine methyl transferase as modulators of hepatic triglyceride metabolism. Therefore, our "systems biology" approach revealed hitherto unrecognized insights into the triglyceride-lowering and anti-atherogenic mechanisms of extra virgin olive oils, wherein the up-regulation of a large array of anti-oxidant enzymes may offer sufficient protection against lesion development and diminish oxidative stress levels instigated by hepatic steatosis.